7. In case of pain, patient agrees to use only paracetamol mono- (max 4 g/day) or combination preparation and oral and/or topic NSAIDs during the trial and to discontinue the use of oral and/or topic NSAIDs and/or paracetamol combination preparation 1 week before each visit whereas the use of paracetamol mono-preparation (max 4 g/day) is allowed. However, in the morning of the visit day, no pain medication is allowed. However, in the morning of the visit day, no pain medication is allowed. Other pain medications are allowed during surgical operation and may be taken for a period not exceeding 4 weeks after surgery.